Very very icy mountain as noted in other reviews.
It's actually dangerously so.
I hurt my hand and have seen others that got hurt there (while I was at their care center) due to the icy conditions.
Falls that normally wouldn't effect you are amplified due to the hard icy surface.
Be very careful if you come here. I would say that it's worth the peace of mind to go 30 mins further up to Alpine if you really want something close to Chicago.
On the flip side, I found that the staff were very friendly contrary to some of the reviews here.